Controllable pitch propeller



P 29; 1953 A. s. ODVEVSEFF 2,653,670

I CONTROLLABLE PITCH PROPELLER Original Filed June 2, 194a 3 Shee ts-Sheet l Sept. 29, 1953 A. s. ODEVSEFF 2,653,670

. CONTROLLABLE PITCH PROPELLER Original Filed June 2, 1948 I 3 Sheets-Sheet 2 BY I M Sept. 29, 1953 A. s. ODEVSEFF CONTROLLABLE PITCH PROPELLER Original Filed June ,2, 1948 5 Sheets-Sheet 3 II III 'llfllllfllllllfvllll r WWW 44.. A

Patented Sept. 29, 1953 CONTROLLABLE PITCH PROPELLER Alec S. Odevsefi, Wichita, Kans., assignor to Beech Aircraft Corporation, Wichita, Kans., a corporation of Delaware Original application June 2, 1948, Serial No.

30,637, now Patent No. 2,618,348, dated November 18, 1952. Divided and this application September 19, 1951, Serial No. 247,264

The invention here disclosed is a controllable pitch propeller and a division of copending patent application Serial No. 30,637, filed June 2, 1948, now Patent No. 2,618,348 of November 18, 1952.

ing adjustments.

22 of Fig. 1;

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tion.

5 together about the central sleeve portion of the General objects of the present invention are hub. to provide practical and efficient hydraulic In the forms of the invention illustrated the: mechanism for effecting the pitch changing adpropeller has a flanged mounting and the con-- justments of the propeller blades and to so contral drive sleeve 20 is therefore part of the.- struct this mechanism that it will be accommomounting flange 2|, Figs. 1 and 4. dated within the hub structure of the propeller. The pitch changing yoke which directly ac- Further, special objects of the invention are tuates the blades, is supported between sliding: to provide the hydraulic pitch adjusting mechabearings in the hub in the space immediately nisrn in a symmetrical, balanced form of consurrounding the central drive sleeve, closely adstruction which will cooperate fully in the proper joining the inner ends of the blades. functioning of the propeller and which While The sliding bearings mentioned are provided. small in size for containment in the hub strucby rigidly connected parallel push rods. ture, will afiord necessary power for pitch changrods are shown at 22, sliding at their opposite ends in inner and outer bearing sleeves 23, 24,.

Other desirable results attained by the invenin the hub I2, in parallel relation at diagonally tion are set forth and will appear in the course opposite sides of the drive sleeve. of the following specification. arrangement, as indicated in Fig. 2, brings the:

The drawings accompanying and forming part rods close to the inner ends of the blades and of the specification illustrate present preferred the thrust transmitting bolts I! close to the rods. embodiments of the invention but structure and The inner ends of the bearing sleeves 23, 24, arrangement may be modified and changed as are spaced far enough apart for full movement regards immediate illustration, all within the of the yoke supported on the rods between these true intent and broad scope of the invention as bearings, hereinafter defined and claimed. The thrust yoke I8 is a rigid ring, rigidly hold- F 1 n the drawings is a broke a d subing the slide rods in spaced relation and guided stantially central longitudinal sectional View by these spaced parallel rods in accurately through the hub of the propeller as on approximaintained alignment between closely adjacent mately the plane of line II of Fig. 2; bearings at opposite sides of the same.

Fig. 2 is a front and broken part transverse rigid relationship the parts are maintained in sectional view of the propeller sectioned portion free sliding mounting, clear of binding or twistappearing as on substantially the plane of line ing effect and requiring but a mini of effort to apply the pitch changing adjustments to Fig. 3 is a broken horizontal sectional detail of the blades. The parts can be made to fit acthe yoke and one of the slide rods carrying the curately and closely to avoid slip or lost motion sam w th pa app arin as on substa ly to which might lead to any difierence in pitch bethe plane of line 33 of Fig. 2; tween the blades.

Figs- 4 a 5 e broken longitudinal and The construction disclosed is particularly well transverse sectional view r p v ly, f a suited to hydraulic operation for, as shown in modified form of the hydraulic operating mecha- Figs. 1 and 4, a hydraulic cylinder 46 may be mounted in the inner end of the hub sleeve, con- Figs. 6 and 7 are broken sectional details of the taining a piston 41 for connection with the push leverage connections between the piston rod and rods. thrust rods in this modified form of construc- In Fig. 1 the hydraulic piston 41 is shown as havin a tubular piston rod 48 guided through In the several views the blades [0 of the proa bearing 49 at the front and carrying a transpeller are shown rotatably supported by bearverse yoke 50 connected with forwardly extended ings at H in the hub body 12 and as adjusted end portions 5| of the push rods 22. axially through the medium of slide blocks l3, This construction provides a short stroke, pow- Fig. 2, engaged in radial slots M in the inner erful piston action having the same longitudinal ends of the propeller retainer rings I5. m ve t as the thrust rods- The blocks 13 thus serve, in effect, as sliding 1 Claim. (01. -16032) crank pins for rotating the blades to various selected pitch angles. They are shown as pivotally engaged over the heads l6 of bolts I! which fasten the ends of companion yoke segments I8 These- This diagonal In this Where greater power may be required and a 3 longer piston stroke is permissible, a construction like that shown in Figs. 4 to 7 may be employed.

In this. modified form of the invention; the forward. endof the. tubular piston. rod 52. is shown pivotally connected at 53 with the longer arms of levers 54 fulcrumed at their outer ends to the hub body, as shown at 55, and pivotally connected at 56 with the extensions 51' on theforward ends of the slide rods 22.,

In both the constructionsshowmtheoperatm fluid, such as oil, may be admitted to and exhausted from the cylinder through a singletransfer line such as indicated at: 58; in Figs. 1 and" 4. Centrifugal force creates, a, tendency for the. blades to go into flat pitch, applying rearward pressure on the piston. Consequently there is no need for fluid or other applied pressure on the forward side of the: piston. Normally fluid pressureior pitch contmlis;undercontrol of: the propeller governor; on? the engine, increasing or. decreasing in pressure as needed, to maintain the desired pitch, and it is. only'necessary' that this pressure fluid reachthe piston. throughthe one connection shown at 58.

The hydraulic. operating mechanism disclosed is simple in construction, symmetrical and fully balanced and is, such as can be wholly: disposed within the centraldrive; sleeve.

What is claimedis:

A- controllable pitch, propeller comprising a hub having an axially: disposed drive sleeve extending therethrough from: front: to back, said drive sleeve having.- a mounting flange at the back and having'aguide atthe front end Of the same, said drive; sleeve having a cylinder forming section within the. backportion' of thesame, a piston, operable; in said cylinder forming section, means for-supplying: and exhausting actuating fluidto. and from; said cylindersection in back of said piston. a. piston. rod extending 4 forwardly from said piston through said guide at the front end of the sleeve, push rods within the hub at opposite sides of and parallel with said, drive sleeve and with the piston rod operating. within said drive sleeve, a thrust ring fixed on intermediate portions of said rods surrounding and freely operable longitudinally over said drive sleeve, propeller blades journaled in the hub' with their inner ends closely adjoining said thrust ring, pitch changing connections from said thrust ring to the inner ends of said blades bearingsv for said push rods supported in the hub at. opposite sides of said thrust rin and longitudinally spaced to permit limited longitudinal pitch changing adjustment of said thrust ring, said spaced bearings being parallel with said drive sleeve and with the piston rod operating through said drive sleeve, and transverse operating connections extending from the forward end of the piston rod in the drive sleeve to. theforward ends of said push rods at the opposite sides of the drive sleeve and whereby substantially all parts of the pitch changing mechanism are contained Within the hub forward of the mounting flange and in generally parallel relationship with the drive sleeve.

ALEC S. ODEVSEFF.

References Cited in the flle of this patent UNITED STATES PATENTS Number Name Date Re. 20,283 Caldwell Mar. 9, 1937 1,403,775 Hart Jan. 17, 1922 1,889,767 Altieri Dec. 6, 1932 2,498,110 Lathreml Feb. 21, 1950 FOREIGN PATENTS Number Country Date 301,635 Germany Apr. 7, 1920 318,377 France June 24, 190 

